There is a known process and plant for rubber-containing waste recycling (RU Patent No. 2460743, IPC C08J11/20, published 10 Sep. 2012).
The plant for processing rubber-containing waste comprises a reactor, a filter, heat exchange equipment, and separation equipment. The reactor consists of two sections: crumb rubber thermolysis section and carbon black marketable conditioning section; both sections are united with a common filter arranged between the sections, and with a spiral solid product propulsive conveyor arranged inside the reactor, with a rotating spiral used as the propulsion unit, or with both sections used independent of each other, each provided with its own filter and spiral.
The plant uses a stainless wire gauze filter with short-pulse washing with gas produced in the thermolysis process, by compressing it in a compressor to separate condensate of heat transfer agent, a synthetic crude component.
The drawbacks of the said device include:
1. Incomplete extraction of liquid fraction (oil) from the gas flow, as a result losing some valuable liquid products. This is caused by air-washing the produced carbon black with adsorbed oil, the cord fabric being completely burnt, some of the oils burnt, and some carried away with flue gases.
2. Low quality of carbon black due to oil adsorption, so that to remove some of the oil, carbon black is air-washed; as a result, the carbon surface oxidizes and its quality deteriorates.
3. High energy consumption of the process dictated by the necessity to use a circulating heat transfer agent, which has to be separated from hydrocarbon vapors generated in thermal decomposition of rubber, then to be heated in a heat exchanger, evaporated, and superheated in a furnace prior to feeding to the reactor.
There is a known pyrolysis furnace (RU Patent No. 2441053, IPCK F23G5/027, C10B 53/00, published 27 Jan. 2012).
The furnace comprises a bin, a screw press, a heating chamber with pyrolysis gas burners, where a flow damper is arranged inside the screw casing at an angle to the feedstock movement direction, and where pyrolysis screw conveyors with their flow dampers are installed above this screw against the feedstock movement, as a rule more than one, each screw conveyor generally being driven from one motor with a reduction gear, the upper screw conveyors having pipes connected to them for removal of pyrolysis gas for value-added use and operation of the heating chamber burners, and the lower screw conveyor for feedstock charging having openings for steam escape to the heating chamber, where the heating chamber has water boiler pipes on its side walls and under the roof to utilize heat from the burners.
The drawbacks of the said furnace are:
1. Incomplete extraction of the liquid fraction (oil) from the gas flow, resulting in the loss (burning in the heating chamber burners) of a part of valuable liquid products, with high pollutant emission to the environment due to inability to provide complete burning of pyrolysis gases with a high resin content in the heating chamber burners.2. Low quality of solid pyrolysis products due to residual hydrocarbons (volatile products), which cannot be separated in the process of drying, therefore additional thermal treatment of the said products is necessary at a high temperature of about 800° C.3. High energy consumption of the process due to heat losses in the process and the need to increase the temperature in the furnace to 800° C.
There is a known method and device for steam thermal processing of rubber waste (Patent BY13279, IPC C08J11/00, C10B53/07, published 2010 Jun. 30).
The device comprises a heating chamber housing a reactor consisting of two equal parts contained in a jacket and arranged in a vertical plane horizontally one above the other and connected in series for pouring waste from the upper to the lower part, each part being provided with a screw and a vapor superheater a vapor superheater in the form of a coil pipeline wound along the length of the jacket, whose inlet is connected to the superheater and whose outlet is connected to the jacket at the inlet of the reactor's upper part, with the heating chamber being connected on the waste loading side to the outlet of the fuel burning chamber, the chamber's outlet being connected to the steam generator; the reactor's upper part is connected with a pipe to the waste loading screw provided with a bin with a water sluice gate, and connected with a pipeline to three condensers connected in series, where the flammable gas outlet from the third condenser is connected to the fuel burning chamber, and the reactor's lower part is connected with a pipe to the discharge bin with a water sluice gate, connected to which with its inlet is the discharge screw, whose outlet is connected to the inlet of a drum dryer, whose inlet is connected with a pipeline to the outlet of combustion products from the steam generator, and whose outlet is connected in series to the solid products discharge screw and the combustion product gas cleaning filter connected to a flue gas stack.
The drawbacks of the said device are:
1. Incomplete extraction by the condensers of the liquid fraction (oil) from the gaseous products of worn tires pyrolysis, resulting in the loss (burning in the burning chamber) of a part of a valuable component of the liquid fraction, and liquid fraction contamination by fine dust generated during solid product disintegration in the screws' operation and is carried away from the reactor with a flow of gaseous decomposition products to a condensation system.
2. Low quality of solid worn tire pyrolysis products due to residual hydrocarbons (volatile products), which cannot be separated in the process of drying, therefore additional thermal treatment of the said products is necessary at a high temperature of about 600-800° C.
3. High energy consumption of the process due to large heat losses during the tire pyrolysis in the reactor, and heat losses in the condensers (heat taken away with cooling water).
The closest to the present invention is the method is the method of thermoplastic waste processing and the plant for its implementation taken as prior art (RU Patent No. 2459843, IPC C08J11/04 (2006.01), published 27 Aug. 2012).
The thermoplastic waste processing plant comprises a waste pre-treatment assembly, an assembly for thermal decomposition of the products into a vapor-gas mix and solid residue, and a vapor-gas mix fractionation system. The thermal decomposition assembly comprises a reactor inclined at an angle to the horizon, arranged in the heating chamber with burners for gaseous fuel and a gas duct for removal of gaseous fuel combustion products, and provided with devices for solid residue discharge and vapor-gas mix removal, where a screw is arranged inside the reactor whose drive is installed outside the reactor, and the vapor-gas mix removal device consists of a gas duct provided with a heating jacket with shutoff valves installed on it, whose inlet is connected to the gas duct for extraction of the reactor's heating chamber gaseous fuel combustion products and whose outlet is connected to the feeder's heating jacket, the vapor-gas mix extraction device being connected to the vapor-gas mix fractionation system, which contains two air cooling condensers installed in series, with air supply and exhaust pipes, and a cyclone filter connected with gas ducts to gaseous fuel burners of the reactors heating chamber.
The drawbacks of the said device are:
1. Incomplete extraction of waste pyrolysis gaseous products by the liquid fraction fractionation system, resulting in the loss of a part of a valuable component of the light fraction, and liquid fraction contamination by fine dust generated during solid product disintegration in the screws' operation and is carried away from the reactor with a flow of gaseous decomposition products to a condensation system.
2. Low quality of solid waste pyrolysis products due to residual hydrocarbons (volatile products), which cannot be separated in the process of drying, therefore additional thermal treatment of the said products is necessary at a high temperature of about 600-800° C.
3. High energy consumption of the process due to large heat losses during the waste pyrolysis in the reactor, and heat losses in the condensers (heat taken away with cooling water).